Book of Thinkage

Thinkage (defined in the book as "the result of mental excretion") presents a bittersweet account of family life full of love and irony, compassion and whimsy. Nothing is off-limits here, as Pa shares with his son the benefits of underachievement, turns pooping into a game and helps Grampa to build a pyramid that attracts energy. Nothing comes from nowhere, Grampa believed, because something always originates somewhere. Whenever his son exhibited obstinacy, resilience, opinionated pigheadedness, Grampa said that these qualities Pa had inherited from his mother.
But as soon as his son demonstrated wit, rational thinking and sophistication, Grampa only smiled and said nothing, because wasn't it obvious where that came from?